KING KUTTER'S BOX BLADES are designed for rugged use by landscapers, farmers, homeowners, and in light construction. They are great for landscaping, land leveling, backfilling, grading, and many other applications. Each box blade is constructed with a 20" specially formed self cleaning moldboard. They have 2 high carbon steel reversible cutting edges (one front and one rear). Each unit features heavy duty, ripper shanks with replaceable, heat treated teeth. Each shank has 4 position adjustment holes that pin to the reinforced frame for maximum efficiency. The shank housing is a 1/4" x 4" x 4" box with slotted holes and pins. The frame is fully welded.